Questions tagged [supernova]

Questions regarding stars which increase suddenly in energy output due to an explosion which ejected much of its mass.

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Why are type 1b and type 1c supernovae called type 1 rather than type 2; if they result from large exploding stars, rather than accreting dwarfs?

What similarities do types Ib and Ic supernovae have in common with type 1a? Are their spectra or their magnitudes more similar to accreting white dwarfs than the other supermassive, main sequence, ...
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Type Ia supernova by fallback?

Is it possible for a massive star of more than 1.4 solar masses (probably around 3 or more but below the threshold for type II) to collapse into a white dwarf and a planetary nebula, then go supernova ...
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Why is the carbon/oxygen ratio at low metallicities important to study?

Oxygen and carbon are the most abundant elements in the Universe (formed via stellar nucleosynthesis), following only hydrogen and helium (formed via the Big Bang). There seems to be a lot of work to ...
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How come a "failed supernova" is, well, "failed"?

I heard about this a while ago but recently came back to it: https://en.wikipedia.org/wiki/Failed_supernova which suggests that basically what this is is something where a star is so big and heavy ...
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Cosmology context plotting : Covariance matrix - Script to plot Omega_m vs Omega_Lambda diagram in Python

I have covariance matrices and Markov chains coming from the SCP (Supernova Cosmology Project) and I would like to plot all these data in the particular diagram Omega_Lambda vs Omega_m or w vs Omega_m....
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Effects of a supernova shockwave or gravitational wave to a nearby planet's orbit?

I've been reading about recent reports regarding COCONUTS-2B, a planet with the longest orbital period known - 1.1 million years. As a previous question asked, What precisely leads to planets like ...
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Can we estimate the number of stars which have died in the observable universe?

We know there are currently between 10^22 and 10^24 stars in the observable universe, but can we make an estimate of how many stars have died so far? Or, in other words, how many supernovæ have taken ...
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How can we know if a star which is visible in our night sky goes supernova?

Let's say there is a star about 3000 light-years away from earth visible in our night sky. If this star were to go supernova tomorrow(not relative to earth's night sky), we would know about it 3000 ...
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How does pair production cause a pair-instability supernova instead of leading to the formation of a black hole?

The Wikipedia article on pair-instability supernovas (PISNs) doesn't seem to give a very good explanation of what causes a PISN. My understanding of the process it describes is this: Once the core ...
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Procedure to construct a spectral energy distribution and bolometric light curve of supernovae?

Can anyone check the logic of this proposed workflow and/or point me in the direction of a guide and example to check my work? Proposed procedure to construct a spectral energy distribution and ...
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Do all C-O white dwarfs have more-or-less the same proportions of carbon and oxygen?

Type 1a supernovae are known for having very consistent energy yields, and they are caused when a carbon-oxygen white dwarf reaches the Chandrasekhar limit of about 1.4 solar masses. Since type 1a ...
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What does an electron-capture supernova leave behind? A white dwarf, a neutron star or nothing?

Somehow, none of the many articles I've read about the recent discovery of electron-capture supernovae has specifically said what they leave behind as remnants.....
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Infall velocity in core-collapse supernovae

In this article Neutrino Transport in core-collapse supernovae, in the description of core-collapse supernova mechanism, it is stated that The velocity of infalling matter in the core increases as we ...
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Is oxygen an alpha element?

Type II (core-collapse) supernovae occur shortly after star formation and enrich a galaxy with $\alpha$ elements such as O, C, NE, Mg, Ca and Si. On the other hand, Type Ia supernovae occur on a more ...
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Difference between Supernova Type Ia and Nova

What is the difference between Supernova Type Ia and Nova? Base on a web search, they seem to have a similar formation process, as they are both white dwarfs in a binary system who absorb masses from ...
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Why is so much energy released in a supernova while so little in a star?

There is a huge amount of energy released in a supernova. All fuel is used almost instantaneously. Why doesn't this happen in stars (like the sun)? I am asking "Why does a large star spend ...
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Nearby galaxy distances

Type Ia supernovae are extremely useful in measuring the distance of remote galaxies. It is known that type Ia supernovae always reach the same brilliance at their peak. Like Cepheid variables, they ...
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Missing supernovae in the Milky Way

Stars with more than 8-16 solar masses usually go supernova. These are OB stars, of which 0.2% currently exist in our galaxy. The average lifespan of said star ranges from 10 to 40 million years. So ...
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How loud would a supernova, kilonova, and hypernova be? [closed]

If we could hear the sounds of these explosions directly where it was happening, how loud would each of these events be?
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Were there any images of Sanduleak -69 202 (progenitor of SN1987A) before it exploded?

We all know about SN1987A, the closest observed supernova since Kepler's time. Its progenitor was Sanduleak -69 202, a magnitude 12 blue supergiant, catalogued in 1970. Were there any images of this ...
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Long-lived supernova remnants?

We cannot see the supernova remnant of the star that triggered the formation of the Sun and the Solar System, as the remnant dispersed and became mixed into the interstellar medium. So I am wondering, ...
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Why does this nucleogenesis table not label s and r-processes for all elements (not-labmade) past Fe?

I'm reviewing nucleogenenesis and came across the table below. I like it because it actually labels the s and r-process elements, but I became confused as to why the neutron capture processes begin at ...
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Uranium accumulating inside a White Dwarf?

A couple of days ago, there was news that "Some dead stars may harbor enough uranium to set off a thermonuclear bomb", which is basically a teaser for Actinide crystallization and fission ...
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How do black holes form from stars that go supernova

I know that the cores of stars with more than 20 times the mass of the Sun collapse into black holes at the end of the star’s life. However, as far as my understanding goes, stars with cores that ...
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How are shockwaves in a star that cause supernova created

I know that during the collapsing of a star 8 times the mass of the Sun at the end of its life, a shockwave is generated that blows the star up. However, I do not understand how it is exactly ...
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What would happen if a neutron star merged with a white dwarf?

We've heard of neutron star mergers and white dwarf mergers. But what would result in a neutron star merging with a white dwarf? Would there be a similar super/kilonova, are there any examples of it, ...
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Can a star be massive enough to go 'supernova' yet not be massive enough to leave behind a neutron star? Or, perhaps vice versa?

From what I understand, stars that explode as a supernova at the end of their lives become either a black hole or a neutron star, and less massive stars that do not explode become white dwarves, but......
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What percent of all stars that have lived (up to now) are stellar remnants?

According to this post, I found that about 90% of all stars are main sequence stars. So I am assuming that the other 10% consists of protostars, older giant stars, and stellar remnants. So I'm ...
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Have there been any confirmed PISN supernovae?

I did some research on pair-instability supernovae (PISN), and wondered if there have been any confirmed superluminous supernovae caused by a pair-instability. Are there any confirmed PISNs out there, ...
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The star that died and became the Crab Nebula and Crab Pulsar?

The supernova of this star was witnessed about 1 thousand years ago, and the star's remains are the Crab Nebula and Crab Pulsar. What is this no longer existent star called? How massive was this star? ...
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When a fast-moving star goes supernova, how will the resulting remnant evolve?

Let's take a massive star that has zero velocity. When this star goes supernova, the resulting supernova remnant will expand in a sphere. But, let's take a runaway star travelling at 200 km/s. I am ...
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Are any of the zodiac stars about to go supernova anytime soon?

I have read that Betelgeuse, known as Ardra in Hindu astrology, could go supernova. Are any of the zodiac stars or the stars of lunar mansions about to become a black hole or supernova?
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After a supernova, why don't new stars coalesce with higher heavier element content?

May be a beginner's question but I couldn't find the answer anywhere. Given a supernova event and the cloud left by it, why does a new star coalesce with a disproportionally higher hydrogen(and helium)...
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What's the safe distance from a hypernova?

Hypernovae are even rarer than supernovae, occuring in stars at more than 30 solar masses, destroying the star that goes hypernova. This post states a hypernova releases several million times more ...
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Can a supernova or a close passing star create a transient sun gravity focus "habitable zone"?

This question was inspired by the previous question Would a black hole passing next to a star create a deadly focal point due to gravitational lensing?. I understand, as gravity also acts on light, ...
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Stellar life cycle flow chart with mass conditions and time scales

I remember that in my nuclear astrophysics lecture a decade ago, our lecturer drew a large flow chart like diagram of stellar evolution in dependence of the mass of the star (in solar units) on the ...
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Where did the hydrogen come from in a type II supernova?

Type II supernovae have hydrogen. Where did the hydrogen come from if that is the first element used up in the star's life cycle? Also if our solar system was seeded from an ancient supernova where ...
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How big would the supernova when a neutron star collides with another neutron star? [closed]

If two neutrons stars that are orbiting were to collide, how big would the supernova explosion be? Would a new black hole or a new supernova remnant be formed?
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How long does it take for a white dwarf to undergo a type Ia supernova?

I read about white dwarfs and their relation to Type Ia supernovae, and I want to know how much time passes between when the white dwarf passes the Chandrasekhar limit and when the white dwarf ...
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Type II supernovae as a distance indicator

Could someone explain in brief exactly how type II supernovae could be used as distance indicators? as in simply the formulae used and how they are employed? I know there are certain methods based on ...
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What is the "shockwave" of a supernova?

A common notion is that supernovae create shock waves in interstellar gas, and can compress them to star forming densities. How is that shockwave transmitted? Is it by ejected (sublight) particles, or ...
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How do you know that the remnants of the explosion of a Star are of a Hypernova?

Some Background? There are many types of Supernovae that can be classified into the following categories :- (This list is available here.) Type 1A supernovae • Their spectra show very little hydrogen ...
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How can many stars be formed from the remains of one supernova?

A supernova is the explosion of a single star; so how is it that thousands of stars can "be born of" that one explosion (presumably only using the unspent fuel / lighter elements of the ...
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How many supernovae events are on their way from within the Milky Way?

The Milky Way has a diameter of around 100.000 light years with the Solar system placed some 25,000 light years from the center. If we assume a supernova rate of 1 per century, and also assume that ...
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Did I see a supernova explosion?

I think I just saw a supernova explode with my own eyes through my GSO 12 inch Dobsonian. Please tell me what it was! I am still trying to find what it was it was mindblowing! I went out on my roof ...
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Would a naked eye supernova become a disc in a matter of days?

Stars are points of light even in telescopes- if they go supernova, their diameter does expand, but given the distance of even nearby stars, they would still be points of light, I suppose? I am asking ...
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What does "located in the Hubble flow" mean?

I do not understand that much about the term Hubble flow. For cosmological studies with type Ia supernova, I often see the sentence like "We used 100 SNe Ia in the Hubble flow". What does ...
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Why did supernova 1987A's "String of 'Cosmic Pearls'" appear to be so lumpy 20 years later? Is it still?

NASA's A String of 'Cosmic Pearls' surrounds an exploding star is beautiful and the page says: This image shows the entire region around the supernova. The most prominent feature in the image is a ...
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How can I estimate the initial luminosity of a SNIa given initial mass of Ni-56?

The initial portion (and peak) of a SNIa's light curve is powered by the $\beta$-decay reaction: $$ ^{56}Ni \rightarrow ^{56}Co + e^+ + \nu_e + \gamma $$ Supposing we know how much Ni-56 is created in ...
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At what distance could a supernova damage the Earth's ozone layer?

As from my latter question it seems Betelgeuse might be much closer than the usually presumed 640 light years. It might be as close as ~440 ly. Suppose it is, would this have any dangerous effects on ...

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